Reading Feedback

Hello Guys,

I am making a simulator that will send only PWM signal to the actuator for simulating a car. I will make a graphical interface to control the duty cycle but, the actuator will ground the signal at certain times for feedbacking. For example 1 sec ground means normal operations, 2-sec ground means overheating.

How can I send the PWM signal and also read the feedbacks?

Thanks in advance,


What actuator? Post a link to its datasheet?

What will cause the actuator to "ground the signal"?

And if "ground a signal" means connecting an Arduino OUTPUT pin to GND when the output is set to HIGH you will almost certainly destroy the Arduino I/O pin.


The actuator will be a thermostat that is a prototype. The ECU simulator will send the PWM signal to the control card of a thermostat. During normal operation, the actuator will send feedback by grounding the PWM signal every 10 seconds for 0.5 seconds. It will also send the error codes in the same way.

I think that using 2 Arduino for that job. One of them will write the PWM signal and one is reading the signal. What do you think about it?

Also, I should send the 24V signal and read the same signal. How could it be possible with Arduino?

Sorry, but I don't understand.

To my mind a thermostat is a device for controlling temperature. I can't envisage why one would connect a thermostat to a PWM signal.

If you are using the word "thermostat" to mean some electronic control board that you are designing then you need to post a schematic for the board.

And, as I said in my earlier Reply it would be most unwise to connect a PWM signal directly to GND.

Finally, I cannot conceive of the circumstances that would require two Arduinos for such a simple task.


This is my fault sorry about it.

There is a control circuit for the thermostat. Normally a car calculates the temperature and sends PWM signal to control card to say how much the cap of the thermostat should open. We want to just simulate this.

So, I want to send PWM signals to the control card of thermostat for just reference that says the opening amount. Also, if there is error the control card will say it by grounding the PWM. I am not really sure how it will ground the signal but basically, the signal remains low for 2 sec. So, there is la double-sided flow. First, I want to solve this problem. After that, I will think about sending and reading the signal at 24v.

I hope I could explain myself :frowning:

That description is a lot more helpful.

I think you mean that the control card opens or closes a valve to regulate the temperature.

I suggest you try connecting the PWM output from the Arduino to the card THROUGH a resistor (perhaps 1000 ohms or more). And connect another Arduino pin set as INPUT to the same connection on the card.

The resistor will protect the Arduino by limiting the current that can flow when the card pulls the PWM signal to GND.

The other pin connected as INPUT can check for the long LOW period.